Foil makes it easy to produce moist and tender ribs every time, and the ribs are more forgiving to temperature spikes while they're in the foil, but there is a down side. Lot's of flavor gets thrown away with the liquid when you unwrap, and the flavors seem to get a little muddled while the ribs are steaming away.
If you're going to use the 3-2-1 Method, the Trigg Method, or any variation using foil for ribs (or butts or briskets for that matter), I think it's a good idea to have a finishing seasoning on hand to recharge the flavors you washed away. For me, a finishing seasoning is a finely ground or powdered variation of the original rub with just a touch more cayenne for kick or some other ingredient for brightness. I don't want to change the flavor profile, just kick it up a notch. I put it on as soon as they come out of the foil, before saucing.
Try it and you just might become a foil convert.